MECHANICAL CHARACTERISTICS OF REINFORCED AND THREE-LAYER SHELLS BASED ON METAMATERIALS, TAKING INTO ACCOUNT OPERATIONAL DAMAGE

Abstract— The conventional design in aeronautical engineering is reinforced shell, which for most structures is a thin shell with a stringer set. This article compares the behavior of a conventional reinforced shell and a spaced shell metamaterial structure with a reinforced set using the example of a main airplane pressure bulkhead. The evaluation criterion is to ensure the required level of residual strength when the limiting state is reached.

NEW SOLUTION TO THE PROBLEM OF A CRACK IN AN ORTHOTROPIC PLATE UNDER TENSION

Abstract— A classical plane problem of the theory of elasticity about a crack in a stretched orthotropic elastic unbounded plane is considered, which leads to a singular solution for stresses in the vicinity of the crack edge. The relations of the generalized theory of elasticity, including a small scale parameter, are given. The equations of the generalized theory are of a higher order than the equations of the classical theory and allow eliminating the singularity of the classical solution. The scale parameter is determined experimentally. The results obtained determine the effect of the crack length on the bearing capacity of the plate and are compared with the experimental results for plates made of fiberglass and carbon fiber reinforced plastic.